Block-signal system.



"No. 859,219. PATENTED JULY 9', 1907.

L. A. HAWKINS. BLOGK SIGNAL SYSTEM.

APPLICATION FILED DBO. 6, 1906.

WITNESSE6. I INVENTOR I Lq UPenCefLH lwk'insg g ff? UNITED STATES P A r NT OFFICE;

LAURENCE A, HAWKINS, OF SCHENEOTADY, NEW YORK, ASSIGNOR TO GENERAL ETFfl'rnIfi COMPANY, A CORPORATION OF NEW YORK.

BLOCK-SIGNAL SYSTEM.

Specification of Letters Patent.

Patented July 9,1907.

Application filed December 5. 1906. Serial 1T0. 346,382.

To all whom it may concern:

Be it known that I, LAURENCE A. HAWKINS, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Block- Signal Systems, of which the following is a specification.

My invention relates to block-signal systems for elec trically operated roads employing the rails as return conductor for the power current, and consists in an immovement in the system described in my former application, filed November 8, 1906, Serial No. 342,455.

In my former application I described a signal system operating on thenormal danger plan, in which both rails were made conductive for all currents without inductive bonds or special connections, and normally open-circuited transformers were connected across the rails at intervals, with means controlled by a moving train for closing a circuit of the transformer ahead of the train to supply current to a track relay, so as to clear the signal for the block which the train is about to enter.

My invention consists in a modification of this system, particularly adapted for the control of signals arranged to give clear, caution and danger indications, and in one aspect consists in so arranging the system that a plurality of transformers have their circuits closed ahead of the train. I secure this result by providing a magnet controlled by a moving train to close the circuit of a transformer ahead of the train in the same manner as in my former application, so that the signal for the block ahead of the train is cleared if the block is unoccupied. And I further provide contacts controlled by the signal for closing the circuit of a second transformer, so as to supplycurrent to a second block in advance of the first, and provide a relay re-. sponsive to current from the second transformer to control the signals to indicate the position of the second block. In this manner, home and distant signals, or three-position signals, may be controlled so as to indicate the condition of two blocks ahead of the train, or in other words, to give clear, caution and danger indications. If the second transformer above mentioned, is adjacent to the first relay, the current from this-transformer will maintain the first relay energized, so that the relay is not gradually short-circuited by an approaching train, as in my former application, but is main tained energized until the train enters the block; at which point means are provided for positively deenergizing the relay. This feature of my invention, consisting in connecting the relay after it is energized to a second source of current, renders the block perfectly definite at its entrance end, and is not limited to signal systems arranged to give three indications, but might be used to advantage where only home signals are employed.

My invention further comprises a number of other features, which will be definitely pointed out in the appended claims, and which will best be understood by reference to the accompanying drawing, which shows a signal system arranged-in accordance with my invention. I

In the drawing, A represents the track rails, which are conductively continuous for all currents, no inductive bonds, or similar device, being required for my system; B represents the third rail, or other working conductor, which is connected to one terminal of the source of power current indicated by the generator C. This generator'may supply either direct current or low frequency alternating current. Its other terminal is connected to the rails through the differential choke coil 0. I

D represents an alternating current generator which furnishes the current for the signal circuits, and is preferably a high frequency generator.

(1 represents line-wires extending from the generator C along the track.

Current is supplied to the track-rails through transforrners E E", the primaries of which are connected to the line-wires d, and the secondaries of which are connected across the track-rails. These transformers are normally open-circuited on either the primary or secondary side. open-circuited on the secondary side. One secondary terminal is connected to the lower rail A, through a resistance, e or 6-, to reduce the flow of power current through the transformer winding.

13 and F represent relays of any suitable type responsive to alternating current of a given frequency, and not to the power current.

member f carrying the relay contact-arm, and two" cooperating windings, one of which, f, is connected across the track-rails through a resistance 0 so as to be supplied with current through the rails when the circuit of an adjacent transformer is closed, and the other,

f is supplied with current of the same frequency and different phase independently oi the track-circuits.

I have indicated a condenserf for the, purpose of obtaining the desired'phase-displacement in the two windings f and f but this may be obtained in any other suitable manner. Each relay controls the circuit of the operating mechanism of a h me and distant signal. Thus, the relay I has its contacts included in the circuit of l he operating mechanism G of the home signal H, and of a distant signal not shown on the drawing. These circuits will be described in detail hereafter.

4 I represents the source of current for the opcmtilw On the drawing I have shown them I have illustrated these relays diagrammatically, as-of the well known induction typo, each comprising a short-circuited secondary mechanism G.- Each home signal is provided with contacts h' h for purposes which will be hereinafter explained.

-K and K represent distant signals with operating mechanisms J and J supplied from the current sources L and L respectively.

M and M represent magnets provided with three armatures m, on and m supplied from sources of current 0 and 0 The magnets M, M etc., are connected to short-circuit insulated rail sections'o, 0 etc., which are inserted in one of the track rails and bridged by a conductor, so that the conductive continuity of the rail is not interfered with. The insulated rail-section, as is shown, forms a convenient arrangement for closing a circuit by a moving train without the use of moving contacts, but it will be understood that the only purpose of these insulated sections is to form a contact device cl'osed by a passing train, and any other suitable form of train-operated circuit closer may be substituted for these insulated sections.

' ,The direction of traffic is indicated by the arrow. Normally, all the transformers E, E etc., are opencircuited, and consequently, all the track-relays F, F, etc., are deenergized, and the signals stand at dangcn The magnets M, M'-, etc., are also normally open-circuited, but whenever a train passes over an insulated section, one of these magnets is energized. Thus, for instance, if a train passes over the insulated section 0, a' circuit is closed from the lower terminal of battery 0 to insulated section o,-th1'ough the car axles to the upper rail A, through this rail to the magnet M and thence to the upper terminal of the battery 0". Magnet M is thus energized and draws up its armatures. Now, let it be assumed that magnet M has just been energized in the manner above described for the magnet M it will then ,have drawn up its armatures, closing a maintaining circuit for itself through its armature .m". The lower armature m will have been shifted from its lower to its upper contact, there by breaking the circuit of track-winding f of relay F, and closing the secondary circuit of transformer E.

' Current then flows'from this transformer through'the traclcrails to the track-winding f of relay E the circuit of this track-winding being closed through the armature m of magnet M The relay F is consequently energized and closes its contact, providedboth rails of the block between this relay and the transformer E are intact, and provided no train is in the block or near enough to the relay on its farther side to shunt it effectually. This shunting distance or overlap is de termined by the relative impedance of the rails and relay, and on the relay design. By using a high frequency current, to which the rails offer a high impe dance, the relay may readily be designed so that this distance is not excessive. A circuit is then closed from the left-hand terminal of the battery I through the contacts of relay F through the armature m of magnet M, and through the operating mechanism G to the right-hand terminal of the battery. The operating mechanism G is consequently energized and draws the signal to clear position. In movingto clear position,

the contacts h, h, carried .by the signal, engage ,the, upper stationary contacts, thereby completing a circuit from the right-hand terminal of the secondary of t'ransformer E fthrough contact h of signal H, to the upper rail A. Transformer E is thus connected-across the track, and supplies current to the track rails. Part of this current passes directly through the track-winding f of relay F assisting in maintaining this relay energized, while part of the current passes to the left to the next track-relay, not shown, which owing to the high rail impedance, is not operatively energized by transformer E. If the track between the transformer E and this track-relay is clear, the track-relay will be energ ized, connecting conductors 1 and 2, thereby closing the following circuit,-from the left-hand terminal of battery L, through conductor 1, to the track-relay, not

shown, thence back through conductor 2, through armature m of magnet M and its back contact, to contact h of signal H, thence through the operating mechanism J of the distant signal K, to the right-hand terminal of the battery L. The operating mechanism J is thereby energized, and the signal K cleared, showing that the track is clear ahead of the train for two blocks. It will be seen that the contact h, while.closing the circuit of transformer E breaks the circuit of transformer E. The purpose of this is simply economy of current. These contacts for opening the circuit of transformer E might be omitted, but by their use, the

transformer E is open-circuited as soon as the signal H is clear and the circuit of transformer E closed, and while the train is still some distance away. Consequently, the high current which would be produced by a train short-circuiting this transformer is saved, and after the signal H is cleared, thetransformer E is no longer needed for energizing the relay F since this relay is then energized by the transformer E It will,

of course, be understood that the contact h should close the circuit of transformer E before opening the circuit of transformer E.

It will be seen that, although thetrack-relay to the left of transformer E is energized, the home signal H will not be affected, since the circuit of its operating mechanism G2 is open at the armature m of magnet M ltwill also be seen that, although -the relay F is energized, the distant signal nextto the right of those shown on the drawings, will not be energized, since its circuit is opened at the back contact of armature m of magnet M. Thepurpose of .this armature m is to prevent any signals being operated, except those which are directly in front of an approaching train.

The "signals H and 70, having been cleared, as above described, no further changes occur until the train reaches the insulated section 0.. When this is reached, the magnet M is short-circuited by the train and drops its arm'atures. The armature m consequently, opens the circuit of operating mechanism G, so that. signal .11 is allowed to return to danger by its counter-weight. In thus moving to danger position, it breaks the circuit of transformer E at contact h, thereby de-energizing-the trackrelay 1?, which accordingly drops 'i'tsarmature. At-

the same time, the presence of'the train on the insulated section 0 serves to complete thecircuit of magnet M as has been heretofore explained, so that its armaturesare drawn up, establishing a new conneotion for the secondary of transfomer E to the track-rails, jso' as to 'maintain the track-relay to. the left of this transformer energized. 'Relay F however, is not energized, although transformer E is still connected tr he track, since the armature m of magnet M in closing the circuit of the transformer, opens the circuit of the track-winding f of the relay F The signal H in going to danger, has opened the circuit of the operating mechanism J of the signal K at the contact h, so that the distant signal K goes to danger, together with the signal H While I have indicated batteries as the sources of current for the signal operating mechanisms and for the magnets M, M etc., it will be understood that any suitable source of current, either direct or alternating, may be used for these devices.

It will further be understood that I have shown the signal operating mechanisms, relays and magnets diagrannnatically, and that in practice, any well known constructions may be employed.

Furthermore, although I have shown my inventionapplied to separate home and' distantsignals for giving the desired indications, it will be understood that my invention is equally applicable to onearm. three-position signals.

-'\(.-cordingly, I do not desire to limit myself to the particular construction and arrangement of parts here shown, but aim in the appended claims to cover all.

modifications which are within'the scope of my invcntion.

What I claim as new and desire to SOCLIII by Letters Patent ol' the United States is,

1. In combination with an electrically-operated road having both rails conductively continuous for an cur-rents, normally opcn-circuited.transformers connected are inter- ,vals across the rails, means controlled by a moving train for closing the circuit of a plurality of transformers ahead of the train, and signal-controlling devices responsive to the voltage impressed on the rails by said transformers.

2. In combination with an electrically-operated road having: both rails conductively continuous for. all currents, normally opcn-circuited transformers connected at intervals across the rails, means controlled ,by a moving train for closing the circuit of a plurality of transformers aheadof the train. signal-controlling devices responsive to the voltage impressed on the rails by said transformers, and signals controlled by said devices adapted to give clear, caution and danger indications.

3. In combination with an electrically-operated road having both rails conductively continuous for all currents, normally open-circuitcd transformers connected at intervals across the rails, means controlled by a moving train for closing the circuit of a plurality of transformers ahead of the train, means responsive to the current supplied to the rails by the transformer nearest the trairi for indicatingthe (ondition of the block ahead of the train, and means responsive to the current supplied to the rails by a second transformer for indicating the condition of a second block ahead of the train.

4. In combination with an electricallyoperated road having both rails conductively continuous for all currents, normally open-clrcuited transformers connected at intervals across the rails, means controlled by a moving train 'for closing the circuit of a plurality of transformers ahead of the train, a track relay responsive to the current sup plied to therails by the transformer nearest the train, a home signal for the block ahead of the train, controlled by said relay, a second track-relay responsive to the current suplied to the rails by a second transformer, and a distant signal controlled by said second relay.

5. In combination with an electrically-operated road having both rails conductively continuous for all currents,

normally open-eirculte'd transformers connected at intervals across the rails, means controlled by a moving train for closing the circuit of a transformer ahead of the train, signal device's responsive to the curren supplied to the rails by said transformer, and means controlled by said devices for closing the circuit of a second transformer.

6. In combination with an electrically-operated road having both rails conductively continuous for all currents, normally open-circuited transformers connected at intervals across the rails, means controlled by a moving train for closing the circuit of a transformer ahead of the train, signal devices responsive to the current supplied to the rails by said transformer, means controlled by said devices for closingthe circuit of a second transformer, and other signal devices responsive to the current supplied to the rails by the second transformer.

7. In combination with an electrically-operated road having both rails'conductively continuous for all currents, normally open-circuited transformers connected at intervals across the rails, means controlled by a moving train for closingythe circuit of a transformer ahead of the train, signal devices responsive to the current supplied to the rails by said transformer for indicating the condition of the block ahead of the train, means controlled by said signal devices forclosing the. circuit of a second transformer ahead of the first, and signal devices responsive to the current supplied to the rails by the second transformer for indicating the condition of a second block ahead of the train.

8. In combination with an electrically-operated road having both rails conductively continuous for all currents, normally open-circuited transformers connected at intervals across the rails, means controlled by a moving train for closing the circuit of a transformer ahead of the train, a track relay responsive to the voltage impressed on the rails by said transformer, a home signal for the block ahead of the train controlled by said relay, contacts controlled by said signal for closing the circuit of a second transformer ahead of the first, a second track relay respon e to the voltage' impressed on the rails by the second; transformer, and a distant signal controlled by the second relay.

9. In combination with an electrically-operated road having both rails conductively continuous for all currents,

normally open-circuited transformers connected at intervals across the rails, means controlled by a moving train for closing thecircuit of a transformer ahead of the train, a track relay connected to the rails ahead of the transformer, and means controlled by said relay for closing the circuit of a second transformer adjacent to said relay.

10. In combination with an electrically-operated road having both rails condnct-ively continuous for all currents, normally open-circuitcd transformers connected at intervals across the rails, means controlled by a moving train for closingthe circuit of a transformer ahead of the train, a track relay connected to the rails ahead of theftransformer, means controlled by said relay for closing the circuit of a second transformer adjacent to said relay, and

connections whereby said relay is de'inergizcd when the train reaches the first transformer.

11. In combination with an electrically-operated road having both rails conductivcly continuous for all currents, normally opcn-circuitcd'transformers connected at intcn vals across the rails, means controlled by a moving train for closing the circuit of a transformer ahead of the train, a track relay connected to the 'rails ahead of the transformer, means controlled by said relay for closing the circuit of a second transformer adjacent to said relay, and connections whereby the circuits of thc iirst transformer and of the relay are opened when t "rain eaches the first transformer.

12. In combination-with an electrically-operateu road having both rails conductively continuous for all currents, a transformer connected across the rails, normally opencontacts in circuit with said transformer, a magnet for closing said contacts, connections from,said magnet'to a source of current arranged to be closed by an approaching train, a track-relay responsive to the current supplied to the rails by said transformer, means controlled by the relay for connecting the relay to a second source of current, a signal controlled by said relay, and means for deenergizing said relay when the train enters the block controlled by said signal.

13. In combination with an electrically-operated road having both rails conductively continuous for all currents, a transformer connected at intervals across the rails, normally open contacts, in circuit with said .transformer, a

14. In combination with an electrically-operated road having both rails conductively continuous for all currents,

a normally, open-circuited transformer connected across the track rails, means controlled by an approaching'train for closing the circuit of said transformer, a track relay responsive to the current supplied to the rails by said transformer, means controlled by the relay for connecting the relay to a second source of current, a signal controlled by said'relay, and means for deenergizing said relay when the train enters the block controlled by said signal.

15. In combination with an electrically-operated road having both rails conductivelycontinuous for all currents, anormally open-circuited transformer connected across the track rails, means controlled by an approaching train for closing the cir'cuitof said transformer, a track relay responsive to the current supplied to the rails by said transformer, means controlled by the relay for connecting the relay to a's'econd source of current, a signal controlled by said relay, and means for opening the circuit of said transformer and disconnecting said relay from the second source when the train enters the block controlled by said signal.

16. in combination with an electrically operated road' employing the rails as return conductor for the power current, normally open-circuited transformers connected at intervals across the rails, elect'romagnets for closing the circuits of said transformers arranged to be successively energized and denergized by a moving train, track relays responsive to the current supplied to the rails by said transformers when their circuits are closed, signals,

controlled by said relays, and contacts in the signal-operating circuits controlled by said elcctromagnets and controlling the signals jointly with the relay contacts.

17. In combination with an electrically-operated road having both rails condu'ctiveiy continuous for all currents,

normally open-circuited' transformers connected at intervals across the rails, means controlled by a moving train for closing the circuit-of a transformer ahead of the train, a track-relay responsive to the current from the transformer, means controlled by the relay for connecting the relay to a second source of'current, means for opening the circuit of said transformer whenthe relay is connected to the second source, and means controlled by'the further movement of the train for disconnecting the relay from the second source. I

18. in combination with an electrically-operated road having both rails conductively continuous for all currents, normally opcn-circulted transformers connected at intervals-across the rails, means controlled by a moving train for closing the circuit of a transformer ahead of the train, a track relay responsive'to the current from the transformer, a signal controlled by said relay, contacts controlled by said signal for connecting said relay to a second source of current and for opening the circuit of said transformer, and means for disconnecting said relay from said second source when the train enters the block guarded by said signal.

in witness whereof, 'I have hereunto set my hand this 3rd day of December, 1906.

LAURENCE A. HAWKINS.

Witnesses:

BENJAMIN B. Hush, Hanan OnroBn. 

